Carburetor fuel nozzle



May 30, 1961 J. T. w. Moen-:LEY

CARBURETOR FUEL NOZZLE 2 Sheets-Sheet l .iwi-fnl Filed Jan. 3l. 1958 INVENTOR. fl/ufs Z` 14./ Mosufy May 30, 1961 J. T. w. MosELEY 2,986,378

CARBURETOR FUEL NozzLE Filed Jan. 5l, 1958 2 Sheets-Sheet 2 M 'wff W 40 36 R I| y' #/48 y 4 bpm/Moc CARBURETOR FUEL NOZZLE James T. W. Moseley, Grosse Pointe Park, Mich., as-

signor to Holley Carburetor Company, Van Dyke, Mich., a corporation of Michigan Filed Jan. 31, 1958, Ser. No. 712,493

2 Claims. (Cl. 261-19) This invention relates generally to carburetors for internal combustion engines, and more specically to nozzles for the delivery of fuel therein.

Carburetors of present design usually employ fuel nozzles which are generally slow in responding to both small changes in air iiow and low air flows. This slow response is believed to be due to at least two factors which are: (l) position of nozzle with respect to the venturi throat; and (2) little or no fuel and air emulsication prior to discharge into the induction passage. In addition to being relatively insensitive, these nozlzes are also characterized by their lack of ability to deliver a thoroughly mixed combustible mixture to the engine.

Accordingly, it is an object of this invention to provide means which will eliminate the foregoing objections.

More specifically, it is an object of this invention to provide a nozzle of novel design which will emulsify the fuel and air prior to discharge into the induction passage and at the same time thoroughly mix the combustible elements so that proper distribution to the engine will be attained.

Other objects and advantages wil become apparent when reference is made to the accompanying illustrations in which:

Figure l is an elevational view with portions thereof broken away and in cross section, illustrating a carburetor embodying the invention.

Figure 2 is an enlarged sectional view taken on the plane of line 2-2 of Figure 6 and looking in the direction of the arrows.

Figures 3, 4 and 5 are fragmentary sectional views similar to Figure 2; Figures 4 and 5 illustrate modifications of the invention.

Figure 6 is a fragmentary enlarged top plan view, with portions thereof cut away and in cross-section, taken on the plane of line 6 6 of Figure l and looking in the direction of the arrows.

Figures 7 and 8 are partially sectioned views illustrating modified constructions of one of the elements shown -by Figure 2.

Referring in greater detail to Figure l, a carburetor 10 having a body 12 and air intake 14 is provided with an induction pasage 16 therethrough adapted to be controlled by a choke valve 18 and throttle valve 20. The induction passage contains a fuel nozzle 22 which communicates by means of suitable conduitry 23 and 25 with a fuel bowl 24 formed to provide a cavity 26 containing fuel therein. The carburetor is securely mounted by any suitable means to the intake manifold 28 of an internal combustion engine.

Figure 2, an enlarged sectional view of the nozzle 22 sectioned substantially on line 2--2 of Figure 6, illustrates the invention in greater detail. The nozzle is generally comprised of conduit portion 30 suitably secured to and communicating with a chamber 3-2 formed by a generally cylindrical structure 34 having one end substantially closed by a cover 36 and the other end enclosed by a conical portion 38. The conical portion has a plurality of apertures 40 therein which are adapted to receive and retain individual discharge conduits 42. One end of the conduit 42 communicates with chamber 32 while the other end 44 is placed so as to be in relatively close proximity to the venturi throat 46.

The upper cover 36 is formed to provide a passage 48, with a somewhat conical depression 50 at one end, cornmunicating between the air within the intake passage i6 and the chamber 32 within the nozzle 22.

Figures 3, 4 and 5 illustrate modifications of the invention in each of which the free end 44 of conduit 42 has been altered in order to obtain different flow characteristics of the nozzle assembly. Figure 3, for instance, has end 44 formed so as to have its edge generally parallel to the normal iiow of air within the intake passage i6. End 44a of Figure 4 is formed so as to present an aperture somewhat open towards the ow of air; this is in direct contrast to end 44b of Figure 5, which forms an aperture that is open in the same general direction as the ilow of air past it.

Figure 6 illustrates the general position of the nozzle assembly within the venturi throat 46 as viewed from a position anterior to the nozzle assembly and with the cover 36 removed. For purposes of illustration, four conduits 42 are shown in communication with the chamber 32 of the nozzle. The number of conduits 42 may be varied, depending upon the requirements of the particular engine. l

Figures 7 and 8 illustrate two modifications of cover 36. The cover 36a of Figure 7 has only a conduit portion 48 with no conical depression 50, as seen in Figures 2 through 5; the cover 36b of Figure 8 has a conduit portion 48 with a relatively large conical depression 50a therein. The effects of these modifications will be discussed later in the specification.

General operation of invention When the engine is operating, fuel is drawn into con duit 30 and subsequently into chamber 32 where it is emulsied with the air, by means of conduit 48, which is rushing past it through the induction passage 16. The resulting fuel-air mixture is then drawn through conduits 42 and discharged into the induction passage.

In general, the resulting emulsitication becomes lighter in weight than raw fuel and because of this, more sensitive to air ows through the induction passage.

During actual tests which were conducted on this nozzle, it was found that responsiveness of fuel ow increased as the ends 44 of conduits 42 approached the venturi throat. Therefore, it becomes apparent that a means of obtaining optimum fuel-air ratio curve characteristics is the relative position of conduits 42 with respect to the venturi throat 46.

Another means of controlling the curve characteristics is by changing the angle of ends 44 of the conduits 42, and Figures 4 and 5 illustrate some of these modications. By having the end shaped as 44a of Figure 4, it is possible to create a ram effect within the conduit 42, thereby leaning out the fuel-air ratio at higher engine speeds and air ilows. If the end were formed as 44b of Figure 5, the fuel-air ratio would be increased because of the added aspirating effect caused by the air ow past the open end 44b. It can readily be seen that any of these modifications or any combination of them can be employed in order to control the flow curve characteristics of the carburetor.

Figures 7 and 8y illustrate modifications of the cover 36. Figure 7 shows a passage 48 of relatively uniform size, extending through the cover 36a. Figure 8 discloses a cover 36b having a passage 48 communicating with a relatively large conical depression 50a on the normally exterior portion of the cover. If cover 36a were employed, a relatively small amount of air would be admitted therethrough, thereby reducing the degree of emulsiiication of the rfuel and air Within Ithe chamber 32. AHowever, if the cover 36h were used, the air wouldstrike thesurface of depression 50a and consequently add a greater amount of air tothe resulting emulsication.

It is apparent that the nozzle provided by the invention is highly iiexible in that it can be adapted to any carburetor on any engine by virtue of the disclosed modiiications. Tests have shown that engines which have been equipped with carburetors employing this invention are generally more responsive to operator demands and have delivered a substantial increase in torque with all other variables being equal. This is due, of course, 'to the sensitivity of the nozzle and its ability to deliver a 'thoroughly mixed combustible mixture to the engine at a -point Where best distribution can be accomplished.

Still other modifications may be mad\e without exceec1- ing the scope of the invention, as defined by the attached claims.

What I claim as my invention is:

1. In a fuel nozzle for a carburetor for an internal combustion engine, an induction passage formedrthrough said carburetor, a venturi formed within said induction passage, means forming a substantially closed emulsifying chamber within said induction passage upstream of said venturi, a main fuel supply conduit adapted to supply fuel to said chamber terminating in said chamber, single air linlet means at the upstream end of said chamber supplying all of the air required to said chamber for controlling the degree of emulsiiication, and means at the downstream end of said chamber for conducting the resulting emulsion to a plurality of points in close proximity to said Venturi.

2. In a carburetor for an internal combustion engine having an induction passage with a venturi formed therein and a fuel reservoir for supplying fuel in metered quantities to said induction passage, a main fuel supply conduit having -its one end in communication with said fuel reservoir and its other end terminating in a substantially closed fuel emulsifying chamber, said chamber being located within said induction passage anterior to said venturi and presented generally within the path of travel of the air passing through said induction passage, single air inlet means forming a ram pipe communicating with the end of said chamber on which said air normally impnges, said ram pipe having a volume less than the volume of said chamberandA servingto supply all of the required air for emulsiiication of said fuel within said chamber, and a plurality of radially spaced downwardly dependingdischarge conduits communicating between said chamber and points in close proximity to the throat of said venturi.

References Cited in the le of this patent UNITED STATES PATENTS 1,791,204 Harel Feb. 3, 1931 1,889,687 Mennesson Nov. 29, 1932 2,145,029 Moseley Jan. 24, 1939 2,574,670 Sweeney Nov. 13, 1951 2,694,560 Olson Nov. 16, 1954 

